Date issued

Jan 12, 2018 - 4:00 PM

Valid until

Jan 13, 2018 - 4:00 PM

Prepared by

stephen holeczi

The snowpack has almost reached tipping point with 40cm of soft snow overlying the Dec. 15 weak layer (surface hoar & facets). Warming temperatures and wind this weekend could push it over the edge at treeline and above.

Regular season
Saturday - January 13, 2018
Alpine

3 - Considerable

Dangerous avalanche conditions. Careful snowpack evaluation,cautious route-finding and conservative decision-making essential.

Natural avalanches possible;human-triggered avalanches likely.

Small avalanches in many areas; or large avalanches in specific areas; or very large avalanches in isolated areas.

Treeline

2 - Moderate

Heightened avalanche conditions on specific terrain features. Evaluate snow and terrain carefully; identify features of concern.

Natural avalanches unlikely; human-triggered avalanches possible.

Small avalanches in specific areas; or large avalanches in isolated areas.

Below Treeline

1 - Low

Generally safe avalanche conditions. Watch for unstable snow on isolated terrain features.

Natural and human-triggered avalanches unlikely.

Small avalanches in isolated areas or extreme terrain.

Sunday - January 14, 2018
Alpine

3 - Considerable

Dangerous avalanche conditions. Careful snowpack evaluation,cautious route-finding and conservative decision-making essential.

Natural avalanches possible;human-triggered avalanches likely.

Small avalanches in many areas; or large avalanches in specific areas; or very large avalanches in isolated areas.

Treeline

3 - Considerable

Dangerous avalanche conditions. Careful snowpack evaluation,cautious route-finding and conservative decision-making essential.

Natural avalanches possible;human-triggered avalanches likely.

Small avalanches in many areas; or large avalanches in specific areas; or very large avalanches in isolated areas.

Below Treeline

1 - Low

Generally safe avalanche conditions. Watch for unstable snow on isolated terrain features.

Natural and human-triggered avalanches unlikely.

Small avalanches in isolated areas or extreme terrain.

Monday - January 15, 2018
Alpine

3 - Considerable

Dangerous avalanche conditions. Careful snowpack evaluation,cautious route-finding and conservative decision-making essential.

Natural avalanches possible;human-triggered avalanches likely.

Small avalanches in many areas; or large avalanches in specific areas; or very large avalanches in isolated areas.

Treeline

3 - Considerable

Dangerous avalanche conditions. Careful snowpack evaluation,cautious route-finding and conservative decision-making essential.

Natural avalanches possible;human-triggered avalanches likely.

Small avalanches in many areas; or large avalanches in specific areas; or very large avalanches in isolated areas.

Below Treeline

1 - Low

Generally safe avalanche conditions. Watch for unstable snow on isolated terrain features.

Natural and human-triggered avalanches unlikely.

Small avalanches in isolated areas or extreme terrain.

Avalanche Problem 1: Persistent Slabs

What Elevation?
Which Slopes?
Chances of Avalanches?
Expected Size?

There is a dangerous weak layer down 30-40 cm but it needs a stiffer slab overlying it for the avalanche to occur. We are "almost" at that tipping point so be very careful with this layer and travel conservatively even if you observe no avalanches.

Travel and Terrain Advice
  • Choose conservative lines and watch for clues of instability.

Avalanche Problem 2: Wind Slabs

What Elevation?
Which Slopes?
Chances of Avalanches?
Expected Size?

Soft windslabs formed during the last storm exist near ridge crests and under cliff bands. Watch for the changing feel of the snow under your feet and be wary of areas with denser surface snow.

Travel and Terrain Advice
  • Use caution in lee areas. Recent wind loading has created wind slabs.

Avalanche Summary

A solo backcountry skier triggered a size 2 avalanche on Richardson's Ridge yesterday outside the Lake Louise Ski Resort boundary - this was a treeline area with a shallow snowpack. As well, numerous small windslabs were observed to have run over the past 48 hours and there has been plenty of settlements being reported at treeline and above.

Snowpack Summary

30cm snow has fallen over the past week with limited wind effect except near ridge crests. There is now a total of 30-50 cm overlying the Dec.15 persistent weak layer of facets and some surface hoar which is becoming reactive at treeline and above. This layer is producing easy to moderate sudden collapse results. Click for an example from today.

Weather Forecast

A warmup is expected starting Saturday with alpine temps in the -3 to 5C range on the Eastern end of the range. Increasing Westerly winds will accompany this and we could see alpine elevation gusts in the 50-80kmh range by the evening with a couple cm of snow. It looks warm through the coming weekend.

Danger Ratings Explained

1 - Low

Generally safe avalanche conditions. Watch for unstable snow on isolated terrain features.

Natural and human-triggered avalanches unlikely.

Small avalanches in isolated areas or extreme terrain.

2 - Moderate

Heightened avalanche conditions on specific terrain features. Evaluate snow and terrain carefully; identify features of concern.

Natural avalanches unlikely; human-triggered avalanches possible.

Small avalanches in specific areas; or large avalanches in isolated areas.

3 - Considerable

Dangerous avalanche conditions. Careful snowpack evaluation, cautious route-finding and conservative decision-making essential.

Natural avalanches possible; human-triggered avalanches likely.

Small avalanches in many areas; or large avalanches in specific areas; or very large avalanches in isolated areas.

4 - High

Very dangerous avalanche conditions. Travel in avalanche terrain not recommended.

Natural avalanches likely; human-triggered avalanches very likely.

Large avalanches in many areas; or very large avalanches in specific areas.

5 - Extreme

Avoid all avalanche terrain.

Natural and human-triggered avalanches certain.

Large to very large avalanches in many areas.

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